Torqueshaft magnetic field measurement systems for gas turbine engines

Abstract

A torqueshaft magnetic field measurement system includes a ceramic package enclosing a magnetoresistive sensor for converting a sensed magnetic field into a differential output voltage, an amplifier for converting the voltage into an amplified sensor signal, and a temperature sensor. An electrical cable connects the ceramic package to an electronic controller with a microprocessor.

1. A torqueshaft magnetic field measurement system comprising:
 a torqueshaft magnetic field sensor, including a first magnetoresistive sensor and a second magnetoresistive sensor, for converting a sensed magnetic field into a first amplified sensor signal and a second amplified signal, respectively, said second magnetoresistive sensor having a field sensitivity axis oriented in a direction opposite to a second field sensitivity axis in said first magnetoresistive sensor; 
 an electrical cable connected to said torqueshaft magnetic field sensor; 
 an electronic controller connected to said electrical cable for receiving said first and second amplified sensor signals, 
 wherein said first magnetoresistive sensor is disposed at a pitch of approximately 0.600 to 0.700 inches from said second magnetoresistive sensor. 
 
   
   
     2. The torqueshaft magnetic field measurement system of  claim 1  further comprising a thermistor producing an electrical signal related to the temperature of said torqueshaft magnetic field sensor. 
   
   
     3. The torqueshaft magnetic field measurement system of  claim 2  wherein said electronic controller comprises a microprocessor for receiving a temperature signal from said thermistor. 
   
   
     4. The torqueshaft magnetic field measurement system of  claim 1  wherein said electronic controller comprises a microprocessor for adjusting said first and second amplified sensor signals to compensate for sensitivity variation in said torqueshaft magnetic field sensor. 
   
   
     5. A torqueshaft magnetic field sensor comprising:
 a first magnetoresistive wheatstone bridge device for converting a sensed magnetic field into a first differential output voltage; 
 a first amplifier for converting said first differential output voltage into a first amplified sensor signal; 
 a second magnetoresistive wheatstone bridge device for converting said sensed magnetic field into a second differential output voltage, said second magnetoresistive wheatstone bridge having a sensitivity axis oriented in a direction opposed to a sensitivity axis of said first magnetoresistive wheatstone bridge; 
 a second amplifier for converting said second differential output voltage into a second amplified sensor signal; 
 a temperature sensor; and 
 a hermetically sealed ceramic package enclosing said first and second magnetoresistive wheatstone bridge devices, said first and second amplifiers, and said temperature sensor. 
 
   
   
     6. The torqueshaft magnetic field sensor of  claim 5  wherein said first and second magnetoresistive wheatstone bridge devices, said first and second amplifiers, and said temperature sensor have an operating temperature range of from −55° C. to 225° C. 
   
   
     7. The torqueshaft magnetic field sensor of  claim 5  further comprising an electrical cable connected to said ceramic package, said electrical cable including at least one of a temperature signal line, a first amplified sensor signal line, a second amplified sensor signal line, a set/reset signal line, an offset signal line, and a power supply line. 
   
   
     8. A torqueshaft magnetic field measurement system comprising:
 a first magnetoresistive sensor for converting a sensed magnetic field into a first differential output voltage; 
 a first amplifier for converting said first differential output voltage into a first amplified sensor signal; 
 a second magnetoresistive sensor for converting a sensed magnetic field into a second differential output voltage, said second magnetoresistive wheatstone bridge having a sensitivity axis oriented in a direction opposed to a sensitivity axis of said first magnetoresistive wheatstone bridge; 
 a second amplifier for converting said second differential output voltage into a second amplified sensor signal; 
 a temperature sensor; 
 a ceramic package enclosing said first and second magnetoresistive sensors, said first and second amplifiers, and said temperature sensor; 
 an electrical cable connected to said ceramic package; and 
 an electronic controller connected to said electrical cable, said electronic controller including a microprocessor for (i) receiving said first and second amplified sensor signals and said temperature signal and (ii) supplying offset signals to the first and second magnetoresistive sensors. 
 
   
   
     9. The torqueshaft magnetic field measurement system of  claim 8  wherein said electronic cable includes at least one of a temperature sense line, a set/reset line, and an offset line. 
   
   
     10. A method for sensing torque applied to a torqueshaft operating in a harsh environment, said method comprising the steps of:
 providing a first magnetoresistive sensor operable in the harsh environment; 
 providing a second magnetoresistive sensor having a sensitivity axis oriented in a direction opposed to a sensitivity axis of said first magnetoresistive sensor; 
 providing on the torqueshaft a circumferential magnetic region which changes magnetization in response to an applied torque; 
 disposing said first and second magnetoresistive sensors adjacent said circumferential magnetic region such that the sensitivity axis of said first magnetoresistive sensor and the sensitivity axis of the second magnetoresistive sensor are both parallel to the torqueshaft and such that a change in said magnetization causes said first and second magnetoresistive sensors to produce first and second sensor signals, respectively, indicative of the applied torque; and 
 applying an offset signal to said first and second magnetoresistive sensors. 
 
   
   
     11. The method of  claim 10  wherein said step of disposing said first and second magnetoresistive sensor adjacent said circumferential magnetic region comprises the step of sensing a change in magnetization in response to a torque applied to the torqueshaft and producing said first and second sensor signals. 
   
   
     12. The method of  claim 10  further comprising the step of amplifying said first and second sensor signals for transmission to an electronic controller. 
   
   
     13. The method of  claim 10  further comprising the step of providing a temperature sensor adjacent said first and second magnetoresistive sensors. 
   
   
     14. The method of  claim 10  further comprising the step of enclosing said first and second magnetoresistive sensors in a ceramic package. 
   
   
     15. A torqueshaft magnetic field measurement system comprising:
 a torqueshaft magnetic field sensor, including a first magnetoresistive sensor and a second magnetoresistive sensor, for converting a sensed magnetic field into a first amplified sensor signal and a second amplified signal, respectively, said second magnetoresistive sensor having a field sensitivity axis oriented in a direction opposite to a second field sensitivity axis in said first magnetoresistive sensor; 
 an electrical cable connected to said torqueshaft magnetic field sensor; and 
 an electronic controller connected to said electrical cable for receiving said first and second amplified sensor signals, 
 wherein said electrical cable includes offset signal lines for transmitting offset signals to said torqueshaft magnetic field sensor. 
 
   
   
     16. A torqueshaft magnetic field measurement system comprising:
 a torqueshaft magnetic field sensor, including a first magnetoresistive sensor and a second magnetoresistive sensor, for converting a sensed magnetic field into a first amplified sensor signal and a second amplified signal, respectively, said second magnetoresistive sensor having a field sensitivity axis oriented in a direction opposite to a second field sensitivity axis in said first magnetoresistive sensor; 
 an electrical cable connected to said torqueshaft magnetic field sensor; and 
 an electronic controller connected to said electrical cable for receiving said first and second amplified sensor signals, 
 wherein said electrical cable includes set/reset signal lines for transmitting set/reset signals to said torqueshaft magnetic field sensor.